Epidemiological studies in the highest-risk population, women between 12 and 21 years of age, indicate a prevalence of around 5%. By diagnosis, the prevalence data are 0.31% for anorexia nervosa, 0.77% for bulimia nervosa, and 3.07% for unspecified eating disorders (incomplete cases of anorexia, bulimia, or binge eating disorder). Risk factors for developing an eating disorder in adolescents range from 11% to 18%.